The continuing advances in medical and nutritional science have led to the development of a large number of pharmaceutical and nutraceutical agents which are prescribed or recommended for a variety of indications. In many cases, the efficacy of such agents in clinical settings is unquestioned. However, the established clinical efficacy of an agent is not always realized in the population at-large, owing in part to poor patient compliance.
For example, dietary calcium is an essential nutrient which has been established to play a vital role in building healthy teeth and bones, blood clotting, muscle contraction, and nerve function. In addition to these benefits, it has been suggested that calcium reduces the risk of recurrence of colon polyps. see Baron J. A. et al. New England Journal of Medicine 1999; 340: 101-107. Most notably, calcium reduces the risk of bone loss caused by osteoporosis in both men and women. Not surprisingly, physicians recommend calcium supplements more than any other dietary supplement.
Despite these advantages, it has been estimated that half of all Americans do not consume sufficient amounts of calcium. More troubling, 80% of women, the group at highest risk for developing osteoporosis, do not consume enough calcium.
This deficiency is due in part to the large daily intake of calcium that is suggested by physicians. The United States Recommended Daily Allowance (“USRDA”) of calcium for adults is 800 to 1,400 mg. The National Academy of Sciences, Institute of Medicine recommends calcium intakes of 1,200 mg per day for people over 50 years of age and 1,300 mg per day for people under 19 years of age. In order to meet these recommendations, approximately 2.5 to 3.5 g of calcium carbonate, the must common source of dietary calcium, must be consumed daily to meet the recommendations. However, it is not practical to make tablets containing such large amounts of calcium carbonate. Consequently, supplemental calcium regimens typically comprise administering two tablets daily of 500 to 600 mg of calcium. Conventional calcium tablets are therefore very large and difficult or uncomfortable to swallow. This problem is exacerbated when excipients are also present in the formulation. As with any solid dose pharmaceutical or nutraceutical, large tablet size often leads to poor patient compliance. In addition to calcium supplements, this disadvantage is commonly encountered with tablets having large amounts of active ingredients, such as multi-vitamins and high-dose pharmaceuticals.
In other cases, poor patient compliance may result from the objectionable taste or consistency associated with certain active ingredients. For example, the active agent may be perceived as pasty, dry, dusty, chalky, bitter or may possess an unpleasant aftertaste. Vitamin B complex, for example, is particularly associated with unpleasant taste.
In view of these problems, there have been numerous attempts to deliver active agents in forms which are less objectionable to the consumer. One approach has been to formulate smaller tablets which are more comfortable to swallow. In this regard, special mention may be made of U.S. Patent Pub. No. US2005/0025811 to Levin et al. which discloses calcium carbonate tablets having volumes which are about 20 to about 35% smaller than conventional calcium carbonate tablets.
Other approaches have involved delivering active agents in the form of chewable confections. This approach has received considerable attention because size restraints are not as important as in other oral dosage forms and flavorants may therefore be added in sufficient quantities to mask unpleasant tastes characteristic of the active agent. For example, commercial chewable calcium supplements based on carbohydrate matrices are well known. There are nonetheless certain disadvantages associated with these products. Notably, carbohydrate matrices provide a hydrophilic environment which may promote microbial activity and consequently reduce shelf-life or require the presence of antimicrobial agents in the formulation.
There is a continuing need in the art for oral dosage forms for delivering active agents. It is therefore an object of the present invention to provide comestible compositions comprising active agents which present desirable organoleptic attributes (i.e., taste and texture) to the consumer. It is also an object of the present invention to provide comestible compositions comprising active agents which mask unpleasant tastes and textures associated with the active agents. It is further an object of the present invention to provide comestible compositions comprising active agents which are resistant to microbial activity.